Messages in this thread | | | Date | Thu, 10 Jun 2021 15:38:01 +0530 | From | Pratyush Yadav <> | Subject | Re: [PATCH] mtd: spi-nor: write support for minor aligned partitions |
| |
On 08/06/21 02:07PM, John Thomson wrote: > Do not prevent writing to mtd partitions where a partition boundary sits > on a minor erasesize boundary. > This addresses a FIXME that has been present since the start of the > linux git history: > /* Doesn't start on a boundary of major erase size */ > /* FIXME: Let it be writable if it is on a boundary of > * _minor_ erase size though */ > > Allow a uniform erase region spi-nor device to be configured > to use the non-uniform erase regions code path for an erase with: > CONFIG_MTD_SPI_NOR_USE_VARIABLE_ERASE=y > > On supporting hardware (SECT_4K: majority of current SPI-NOR device) > provide the facility for an erase to use the least number > of SPI-NOR operations, as well as access to 4K erase without > requiring CONFIG_MTD_SPI_NOR_USE_4K_SECTORS > > Introduce erasesize_minor to the mtd struct, > the smallest erasesize supported by the device
Instead of having just a major and minor erase size, wouldn't it make more sense to have a list of all supported erases on a sector? That is, instead of hard coding two erase size instead of one, how about generalizing the erase machinery to allow any number of erase sizes on a sector and then choosing the most efficient one on run time?
For example, imagine a device can support 4K, 64K, and 256K erases on each sector. Then you should be able to use 2 x 4K erases if you want to erase 8K, 2 x 64K + 1 x 4K erases for 132K and so on.
I am not very familiar with MTD erase machinery so I would like someone else to chime in, but I think my suggestion above is the better way forward.
-- Regards, Pratyush Yadav Texas Instruments Inc.
| |